Publication details
Thick-skinned deformation in variscan fold and thrust belt: an evidence from brunovistulian terrane
| Authors | |
|---|---|
| Year of publication | 2018 |
| Type | Article in Periodical |
| Magazine / Source | Geology, Geophysics & Enviroment |
| MU Faculty or unit | |
| Citation | |
| Keywords | Brno Massif; Thick-skinned deformation; Fold and Thrust Belt; Brunovistulicum |
| Description | The eastern margin of Bohemian Massif is well exposed part of Variscan Orogenic Front, where the detail structural relations can be studied. The megastructures of the area are results of collision between Brunovistulian terrane and a rest the of Bohemian Massif (Fig. 1a). This work is focussed on processes and structures in the lower block (e.g. Brunovistlicum). Structural analysis supported by anisotropy of magnetic susceptibility analysis reveals same Variscan deformational origin for mesoscopic and magnetic fabrics in Brno Massif – the biggest uncovered area of Brunovistulicum. The rock fabrics are flexing from NNE-SSW striking and steep western dipping on the north to NW-SE striking with NE dipping on the south. Similar changes in direction is apparent as well in lithological zoning of Brno Massif rocks suggesting a regional fold (Fig. 1b). Fold axis is slightly plunging to the north enabling profile construction using the down plunge method. Overthrusted fold limb consists of repeated simple sheared thrust sheets with increasing intensity of deformation to the north originated in dextral transpresional regime. These facts lead to a conlusion that there is a large-scale fold as a product of late Variscan deformation developed together with Moldanubian Thrust. This regional structure shows a propagation of orogene to its foreland incorporating the lower block to a megastructure similar to the fabrics in recent orogenes. Proving the same mechanisms and intensity of deformation in Variscan and Alpine orogenes allows the application of known fabrics from current orogenes to the older ones. |